 #include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <Stdbool.h>
 
 struct TreeNode {
      int val;
      struct TreeNode *left;
      struct TreeNode *right;
  };
 
int maxDepth(struct TreeNode* root) {
    if(root==NULL)
        return 0;
    int val1 = maxDepth(root->left);
    int val2 = maxDepth(root->right);
    int big = val1>val2?val1:val2;
    return 1+big;
}